Drill bit



W. L CHILDS.

DRILL BIT.

APPLlCATlOll FILED JAN.13, 1920.

1,406,931 Patented Feb. 14, 1922.

, rwenfoz 2934 @in an'OM /QWM 4P \SGYLQ UNITED STATES PATENT OFFICE.

W ILLIAM L. GHILDS, OF HOUSTON, TEXAS, AS SIGNOR TO HUGHES TOOL COMPANY,OF HOUSTON, TEXAS, A CORPORATION OF TEXAS.

DRILL BIT.

Specification of Letters Patent.

Patented Feb. 14, 1922.

To all whom it may concern:

Be it known that 1, WILLIAM L. claims, a citizen of the United States,residing at Houston, Harris County, Texas, have invented a certain newand useful Improvement in Drill Bits, of which the following is a full,clear, and exact description, such as will enable others skilled in theart to which it appertains to make and use the same.

My invention relates to an improvement in drill bits, but has particularapplication to the type of bit ordinarily used in drilling in softformation, such as clay, gumbo or similar material.

The object of my invention is to provide a means for preventing thesticking of the material to the drill and drill collar while thedrilling operation is being performed.

Referring to the. drawings forming a part of this specification andwherein like parts are designated by like numerals of reference in boththe views, Fig. 1 is a side elevation of a fish tail bit with myimprovement thereon; Fi 2 is a central longitudinal section of thedevice shown in Fig. 1 taken at right an les to the position shown inthat figure.

n the drilling of wells and mines for oil, gas, sulfur, etc., the commontype of bit used when operating in soft formation is the fishtail bit,the common form of which is represented in the figures. The difiicultyexperienced while working in soft formation is that the flushing water,which is pumped down through the drill' stem, serving to carry awaythe'cuttings from the bit, and

raising tnem in suspension to the surface of the ground, does not act tocarry away the cuttings with sufficient rapidity to prevent theirforming a ball about the bit, sticking to the blade and shank thereof,and so clov ing the action of the bit that it ceases to unction. It isthe object of this improvement to supply a lubricant to the face of thecutting blade which will act to prevent the sticking of the materialthereto and thus maintain a clean surface at all times and prevent theballing up of the bit.

In Fig. 1 I have shown an ordinary type of fish-tail bit having aflattened blade 3 with a lower cutting edge thereon and an uppercylindrical threaded shank 4 for attachment to the drill collar, notshown. At thev upper end of the shank 4; there is proy ded a threadednipple 5 of reduced diame ter, which is connected by means of a specialcoupl ng 6 to the lubricant container 7, said contalner being covered atthe upper end by a cap 8 threaded thereon.

The coupling 6 is of special construction having therein a valve 9closing a central passage 11 leading from the lubricator 7 downward to asmall chamber 12 within the nipple 5 of the bit. A squared end 10 uponthe valve 9 is provided whereby the valve may be turned to open or closethe passage from the lubricator to the bit.

The lubricant is supplied from the chamber 12 in the upper end thereofto the blade of the bit by means of a series of oil ducts which serve toconduct the oil and lubricant to different portions of the blade. Thereis a central channel 13 leading directly downward through the blade ofthe bit to a point centrally thereof from which there are two branchingducts 13' which feed the oil to the opposite sides of the blade, asshown in Fig. 2. Lubricant is also fed to the uper end of the blade oneach side thereof y two laterally inclined ducts 14 discharging throughopenings 15 onto the face of the blade. Through these series of ductslubricant may be fed upon the blade during the o eration, thereof so asto furnish a film of oi over practically the entire area of the blade.

The lubricant is forced downwardly through the oil ducts 13 and 14 fromthe lubricator by means of a small piston 16 which is adapted to fitsnugly within the tubular lubricant container 7 and to rest upon theupper surface of the oil. The cap 8 is provided with a central opening17 which allows the entrance thereto of flushing Water from within thedrill stem. This water is under pressure, not only from the pumps butfrom the static head within the well. This pressure is exerted upon thepiston 16 and acts to force it downwardly upon the lubricant so as topro 'ect this lubricant through the ducts 13 an 14 to the blade. Thistype of lubricator is not new in the art but is used for a new purposein this relation.

The flushing water within the drill stem is also su plied to the uppersurface of the blade tldrough channels 18 which lead from the upper endof the shank 4 downwardly so as to discharge through openings 19 ontothe upper faces of the blade of the bit. This flushing water acts tocarry away the disinte rated material.

he operation of this invention will now be obvious. The bit is attachedto the drill collar and the drill stem in the usual manner, the bithaving first been provided with the lubricator attachment justdescribed. The length of the lubricant container 7 may be sufficient tohold a supply of lubricant to operate for the desired length of time.The drill may be rotated and the flushing water be discharged during theoperation downwardly through the ducts 18 upon the blade, and thepressure of the flushing water upon the piston 16 will discharge thelubricant slowly through the ducts 13 and 14 onto the face of the blade.The lower cutting points of the blade will, because of their scrapingaction upon the material, maintain themselves clear of the disintegratedmatter, and the discharge of the oil through the ducts onto the face ofthe blade will provide a film of oil which will prevent the adherence ofthe clay or gumbo to the upper part of the blade. It has been found thatthe carrying away of the disintegrated material by the flushing waterwill also cause the oil from the ducts 13 and 14 to be carried upwardlyalong the drill collar and the lower end of the drill stem, serving tocover them alsowith a film of oil, thus also preventing them from beingcovered with the viscous material bein cut by the bit. A fish tail bitthus rovlded with a lubricating means such as lierein shown will Workfor long periods in soft formation without the necessity of' spudding orof withdrawing the bit from the well to clear the same of material.There will be a great saving in time usually consumed in clearing thebit periodically of the material adhering thereto.

Having thus described my invention, what I claim as new and desire toprotect by Letters Patent is:

1. In an earth boring drill, the combination of a fish tail blade, alubricant container thereon, means to conduct lubricant from saidcontainer to the face of said blade and a series of oil ductsdischarging from said.

blade onto its working surface, a nipple on the upper end of said shank,a lubricant container attached thereto, and means to force lubricantfromsaid container downwardly onto the face of the said blade.

In testimony whereof, I hereunto afiix my signature this the 8th day ofJanuary W. L. GHILDS

